Which WM accpets this...

[nupul kukreja]

I wish to make a particular window transparent. I was told that the
particular window manager must accept the atom _NET_WM_WINDOW_OPACITY.
 I was using Qt's inbuilt method for this and it says that this atom
must be accepted. I have used the following window managers but none
of them support this...

fvwm, wmaker, metacity, kwin, openbox, blackbox.

...could you please tell me which WMs today accept this atom?